Cute gibbons playing and climbing

A gibbon is any of approximately 20 species of small apes found in the tropical forests of Southeast Asia. Gibbons, like the great apes (gorillas, orangutans, chimpanzees, and bonobos), have a humanlike build and no tail, but gibbons seem to lack higher cognitive abilities and self-awareness. They also differ from great apes in having longer arms, dense hair, and a throat sac used for amplifying sound. Gibbon voices are loud, are musical in tone, and carry over long distances. The most characteristic vocalization is the “great call,” usually a duet in which the female leads and the male joins in with less-complex notes, used as a territorial marker by both sexes.